Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/06—TPC algorithms
  • H04W52/14—Separate analysis of uplink or downlink
  • H04W52/146—Uplink power control
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B17/00—Monitoring; Testing
  • H04B17/30—Monitoring; Testing of propagation channels
  • H04B17/309—Measuring or estimating channel quality parameters
  • H04B17/345—Interference values
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/18—TPC being performed according to specific parameters
  • H04W52/22—TPC being performed according to specific parameters taking into account previous information or commands
  • H04W52/225—Calculation of statistics, e.g. average or variance
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/18—TPC being performed according to specific parameters
  • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
  • H04W52/243—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account interferences
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/38—TPC being performed in particular situations
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/06—TPC algorithms
  • H04W52/16—Deriving transmission power values from another channel
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/18—TPC being performed according to specific parameters
  • H04W52/22—TPC being performed according to specific parameters taking into account previous information or commands
  • H04W52/226—TPC being performed according to specific parameters taking into account previous information or commands using past references to control power, e.g. look-up-table
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/30—Transmission power control [TPC] using constraints in the total amount of available transmission power
  • H04W52/36—Transmission power control [TPC] using constraints in the total amount of available transmission power with a discrete range or set of values, e.g. step size, ramping or offsets
  • H04W52/367—Power values between minimum and maximum limits, e.g. dynamic range
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W92/00—Interfaces specially adapted for wireless communication networks
  • H04W92/16—Interfaces between hierarchically similar devices
  • H04W92/20—Interfaces between hierarchically similar devices between access points

Definitions

• the present invention relates to a method and arrangement in a first radio network node and a method and arrangement in a second radio network node. More in particular, the present invention relates to a mechanism for reducing channel interference between co- located radio network nodes by supporting transmission power adjustment of a mobile terminal.
• RAT Radio Access Technologies
• GSM Global System for Mobile Telecommunications
• UTRAN UMTS Terrestrial Radio Access Network
• E-UTRAN Evolved UTRAN
• the multifarious technologies may also co-exist in adjacent carrier frequencies in the same band.
• the radio transmission and reception requirements which are specified in the standard, are generally different for different types of technologies.
• E-UTRA supports multiple bandwidths ranging from 1.4 MHz to 20 MHz. Thus the out of band emission requirements of E-UTRAN are adapted to support larger bandwidths.
• E-UTRAN may sometimes also be referred to as Long Term Evolution (LTE).
• LTE Long Term Evolution
• a resource block size is 180 KHz comprising 12 sub-carriers each with 15 KHz carrier spacing and 0.5 ms time slot in frequency and time domains, respectively.
• the Transmission Time Interval (TTI) comprises 2 time slots, which correspond to 1 ms length in time.
• the radio frame is 10 ms long.
• the E-UTRA uplink uses Single-Carrier Frequency Division Multiple Access (SC-FDMA) whereas the downlink uses Orthogonal Frequency Division Multiple Access (OFDMA).
• SC-FDMA Single-Carrier Frequency Division Multiple Access
• OFDMA Orthogonal Frequency Division Multiple Access
• the SC-FDMA can be regarded as a special form of OFDMA. More specifically it is a linearly pre-coded OFDMA scheme resulting in lower Peak to Average Power Ratio (PAPR).
• PAPR Peak to Average Power Ratio
• the lower PAPR implies relatively smaller User Equipment (UE) power back-off, or maximum power reduction, to meet the emission requirements. Due to these reasons the SC-FDMA is considered more suitable for uplink transmission.
• UE User Equipment
• Both OFDMA and SC- FDMA or any variant of OFDMA ensures inter-user orthogonality.
• OOB emission requirements are to limit the interference caused by the transmitters, terminals or base stations, outside their respective operating bandwidths to the adjacent carriers or bands.
• all wireless communication standards such as e.g. GSM, UTRAN, E-UTRAN, Wireless Local Area Network (WLAN) etc, clearly specify the OOB emission requirements to limit or at least minimize the unwanted emissions. They are primarily approved and set by the national and international regulatory bodies e.g. ITU-R, FCC, ARIB, ETSI etc.
• the major OOB emission requirements which are typically specified by the standards bodies and eventually enforced by the regulators in different countries and regions for both terminals and base stations comprises: Adjacent Channel Leakage Ratio (ACLR), Spectrum Emission Mask (SEM), Spurious emissions and/or In-band unwanted emissions.
• ACLR Adjacent Channel Leakage Ratio
• SEM Spectrum Emission Mask
• Spurious emissions and/or In-band unwanted emissions.
• the frequency bands, channel arrangements and radio requirements applicable for the GSM operation are standardized. Also the frequency bands for UTRAN FDD (WCDMA) operation are standardized. The same set of specifications provides a complete set of UTRAN FDD minimum radio requirements including those related to the Out Of Band emissions for mobile terminal and the base station. These requirements are used by the manufacturers to build products such as e.g. mobile terminal and base station.
• E-UTRAN frequency bands and channel arrangements applicable for E-UTRAN operation are standardized.
• the same set of specifications also provide a complete set of E-UTRAN (FDD and TDD) minimum radio requirements including those related to the out of band emissions for mobile terminals and base stations. These requirements are used by the manufacturers to build E-UTRA products such as e.g. mobile terminal and base station.
• GSM bands extended 800 (band V), 1800 (band VII) and 1900 (band VIII); UTRAN FDD bands: VIII, III and Il and E-UTRAN FDD bands: 8, 3 and 2.
• frequency bands 2 GHz and 2.6 GHz are specified for both UTRAN FDD and E- UTRAN FDD: UTRAN FDD bands: band I: 2 GHz and band VII: 2.6 GHz; E-UTRAN FDD bands: band 1: 2 GHz and band 7: 2.6 GHz.
• the UTRAN FDD operation adjacent to an operating E-UTRA carrier is particularly vulnerable to the emissions caused by the E-UTRA carrier.
• the E-UTRA terminal power distribution is higher compared to that of the UTRA terminal. This in turns leads to higher out of band emissions from E-UTRA towards UTRA FDD causing higher degradation in UTRA performance.
• the higher terminal power distribution causes degradation on adjacent systems and can either be handled by more stringent out of band emission requirements, which are not feasible from the terminal implementation point of view. Alternatively this can be addressed more conveniently by controlling the terminal transmission power by means of a suitable power control scheme.
• the uplink power control has both open loop component and closed loop components.
• the former is derived by the mobile terminal in every sub-frame based on the network signalled parameters and estimated path loss or path gain.
• the latter part is governed primarily by the Transmit Power Control (TPC) commands sent in each sub- frame, i.e. active sub-frame where transmission takes place, to the mobile terminal by the network.
• TPC Transmit Power Control
• the mobile terminal transmits its power based on both open loop estimation and TPC commands.
• the mobile terminal sets the uplink transmit power for PUCCH or PUSCH or Sounding Reference Signals (SRS) channels depending upon which of these channels (PUCCH, PUSCH and SRS) are transmitted in a sub-frame.
• SRS Sounding Reference Signals
• the uplink transmitted power for RACH transmission is only based on the open loop components such as i.e. path loss and network signalled parameters.
• the network can also estimate both open loop components, including path loss, and closed loop components of the uplink transmitted power since parameters and TPC commands are transmitted by itself.
• the network is also aware of the total number of active users in a cell. In this way the network may infer the total amount of interference experienced in the uplink due to uplink transmission. This allows the network to set various set of signalled parameters and monitor the consequence of power control on the uplink interference.
• the uplink power control in E-UTRAN is governed by a number of network controlled parameters. Therefore, in E-UTRAN, the uplink power control is highly parameterized.
• the mobile terminal derives its transmitted power for uplink transmission in each sub- frame using the configured parameters in conjunction with the received TPC command and the estimated path loss. This result in that the mobile terminal uplink transmitted power in E-UTRAN is highly sensitive to the parameters set by the network.
• the change in power in one sub-frame can be very large e.g.
• E-UTRA uplink received interference within an operating carrier frequency but also adversely impact the reception quality at the adjacent carriers.
• the uplink in E-UTRA is orthogonal i.e. inter-E-UTRA user orthogonality in the same cell, which mean that high terminal transmit power may not have negative impact on other E-UTRA users.
• a multi-RAT adjacent channel scenario as described herein may occur occasionally.
• the UTRAN FDD capacity loss when E-UTRAN/ LTE is an aggressor may be in the order of 25%, according to some estimations.
• the present solution aims at improving, e.g. optimizing and/ or limiting the values of parameters used for running the uplink power control, at the interfering aggressor system.
• the values of the power control parameters are limited so as to ensure that the performance of the victim system is minimally impacted.
• the bounded power control parameter values may also minimally impact the interfering or the so-called aggressor system.
• the object is achieved by a method in a first radio network node for supporting transmission power adjustment of a mobile terminal.
• the first radio network node and the mobile terminal are adapted to operate on a first radio access technology.
• the adjustment of transmission power of the mobile terminal is performed in order to reduce interference, caused by the mobile terminal, on a second radio network node.
• the second radio network node is adapted to operate on a second radio access technology.
• the method comprises obtaining an indication that the second radio network node is interfered by transmissions from the mobile terminal.
• the method comprises obtaining values of power control parameters for adjusting the transmission power of the mobile terminal.
• the method comprises transmitting the obtained power control parameter values to the mobile terminal, in order to enable the adjustment of the transmission power of the mobile terminal.
• the object is also achieved by an arrangement in a first radio network node for supporting transmission power adjustment of a mobile terminal.
• the first radio network node and the mobile terminal are adapted to operate on a first radio access technology.
• the adjustment of transmission power of the mobile terminal is performed in order to reduce interference, caused by the mobile terminal, on a second radio network node.
• the second radio network node is adapted to operate on a second radio access technology.
• the arrangement comprises a first obtaining unit.
• the first obtaining unit is adapted to obtain an indication that the second radio network node is interfered by transmissions from the mobile terminal.
• the arrangement comprises a second obtaining unit.
• the second obtaining unit is adapted to obtain values of power control parameters for adjusting the transmission power of the mobile terminal.
• the arrangement comprises a transmitter.
• the transmitter is adapted to transmit the obtained power control parameter values to the mobile terminal in order to enable the adjustment of the transmission power of the terminal.
• the object is also achieved by a method in a second radio network node for assisting a first radio network node in supporting transmission power adjustment of a mobile terminal in order to reduce interference, caused by the mobile terminal.
• the first radio network node and the second radio network node are situated at the same geographical location.
• the first radio network node and the mobile terminal are configured for operation on a first radio access technology.
• the second radio network node is configured for operation on a second radio access technology.
• the method comprises measuring the signal interference induced by the mobile terminal. Further the method comprises sending an indication that the second radio network node is interfered by transmissions from the mobile terminal, if the measured signal interference from the mobile terminal exceeds a certain predetermined threshold limit value.
• the object is also achieved by an arrangement in a second radio network node for assisting a first radio network node in supporting transmission power adjustment of a mobile terminal in order to reduce interference, caused by the mobile terminal.
• the first radio network node and the second radio network node are situated at the same geographical location.
• the first radio network node and the mobile terminal are configured for operation on a first radio access technology.
• the second radio network node is configured for operation on a second radio access technology.
• the arrangement comprises a measuring unit.
• the measuring unit is adapted to measure the signal interference induced by the mobile terminal.
• the arrangement comprises a transmitter.
• the transmitter is adapted to transmit an indication that the second radio network node is interfered by transmissions from the mobile terminal, if the measured signal interference from the mobile terminal exceeds a certain predetermined threshold limit value.
• Figure 1 is a block diagram illustrating a wireless communication system.
• Figure 2 is a schematic flow chart illustrating embodiments of a method in a first radio network node.
• Figure 3 is a block diagram illustrating embodiments of an arrangement in a first radio network node.
• Figure 4 is a schematic flow chart illustrating embodiments of a method in a second radio network node.
• Figure 5 is a block diagram illustrating embodiments of an arrangement in a second radio network node.
• the present solution is defined as a method and an arrangement in a first and a second radio network node, which may be put into practice in the embodiments described below.
• the present solution may, however, be embodied in many different forms and may not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present solution. It should be understood that there is no intent to limit the present methods, and arrangements to any of the particular forms disclosed, but on the contrary, the present methods and arrangements are to cover all modifications, equivalents, and alternatives falling within the scope of the present solution as defined by the claims.
• Figure 1 is a schematic illustration over a geographical location 100.
• the geographical location 100 may be referred to as a site.
• the geographical location 100 comprises a first radio network node 110, operating on a first radio access technology.
• the geographical location 100 may further comprise a second radio network node 120, operating on a second radio access technology.
• the second radio network node 120 may optionally be attached to a control node 125, depending on the radio access technology used.
• the geographical location 100 is arranged to comprise at least one mobile terminal 130.
• FIG. 1 is only a non-limiting example of a possible environment, or geographical location 100 wherein the present method may be implemented.
• a plurality of radio network nodes 110, 120 may be co-located at the same site, e.g. with antenna means mounted on the same physical structural element such as e.g. radio tower, according to some embodiments.
• the first radio network node 110 within the geographical location 100 may be arranged to operate on a plurality of radio access technologies, thus sharing certain structural elements e.g. power amplifier.
• the second radio network node 120 may be comprised within the first radio network node 110, according to some embodiments, but operating on different radio access technologies.
• the first radio network node 110 and the second radio network node 120 may be operated by different service providers, and thus not sharing structural elements.
• radio network nodes 110, 120 are illustrated in Figure 1 , it is to be understood that another configuration of radio network nodes 110, 120 may be comprised within the geographical location 100, such as e.g. one, two, three, four, or another plurality of radio network nodes 110, 120, arranged to operate on one, two, three, four, or another plurality of radio access technologies.
• Each of the radio network nodes 110, 120 may also be referred to as e.g. a base station, an access point, a Node B, an eNode B, a base transceiver station, Access Point Base Station, base station router, etc depending e.g. of the radio access technology used.
• a base station an access point
• Node B an eNode B
• a base transceiver station e.g. a base transceiver station
• Access Point Base Station e.g. of the radio access technology used.
• the mobile terminal 130 may be a user equipment (UE) such as e.g. a wireless communication terminal, a mobile cellular telephone, a Personal Digital Assistant (PDA), a laptop, a computer or any other kind of device capable of managing radio resources, adapted to communicate wirelessly with any of the radio network nodes 110, 120 within range.
• UE user equipment
• PDA Personal Digital Assistant
• the radio access technologies used for wireless communication may comprise technologies such as e.g.
• E-UTRAN E-UTRAN, UTRAN, GSM, Enhanced Data rates for GSM Evolution (EDGE), General Packet Radio Service (GPRS), Code division multiple access (CDMA), Wideband Code Division Multiple Access (WCDMA), CDMA 2000, High Speed Downlink Packet Data Access (HSDPA), High Speed Uplink Packet Data Access (HSUPA), High Data Rate (HDR), HRPD Universal Mobile Telecommunications System (UMTS) etc, just to mention some few arbitrary and none limiting examples.
• EDGE GSM Evolution
• GPRS General Packet Radio Service
• CDMA Code division multiple access
• WCDMA Wideband Code Division Multiple Access
• CDMA 2000 High Speed Downlink Packet Data Access
• HSDPA High Speed Uplink Packet Data Access
• HDR High Data Rate
• HRPD Universal Mobile Telecommunications System UMTS
• radio access technologies used within the radio network nodes 110, 120 may further, according to some embodiments, refer to Wireless Local Area Networks (WLAN), such as Wireless Fidelity (WiFi) and Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth or according to any other wireless communication technology.
• WLAN Wireless Local Area Networks
• WiFi Wireless Fidelity
• WiMAX Worldwide Interoperability for Microwave Access
• the optional control node 125 may be e.g. a Radio Network Controller (RNC).
• RNC Radio Network Controller
• the control node 125 is a governing element, responsible for control of the radio network node 120, which are connected to the control node 125.
• the control node 125 may further for example carry out radio resource management; some of the mobility management functions, just to mention some brief examples illustrating some possible functionalities of the control node 125.
• the mobile terminal 130 may further communicate with other terminals not shown in Figure 1 , via any radio network node 110, 120 comprised within the geographical location 100.
• downlink is here used to specify the transmission from the radio network node 110, 120 to the mobile terminal 130
• uplink is used to denote the transmission from the mobile terminal 130 to the radio network node 110, 120.
• the first radio network node 110 is communicating with the mobile terminal 130 using a first radio access technology, which communication cause degradation to the second radio network node 120, adapted to operate on a second radio access technology.
• the first radio network node 110 is part of an interfering system, or aggressor system while the second radio network node 120 is part of a victim system.
• the present method defines a power control parameter value region, e.g. upper bound the power control parameter values such that degradation to the victim system in a coexistence scenario may be below an accepted limit as well as the performance loss in the own-system, interfering system, or aggressor system, may be reduced.
• the region may be determined using simulations or measurement devices.
• the defined power control parameters values i.e. their maximum limit, may be used by the actual devices to keep the degradation below the limit at the victim system in a co- existence scenario.
• the radio network node 110, 120 may take into consideration the maximum i.e. the constrained values of the defined parameters values, when configuring or signalling power control parameters to the mobile terminal 130.
• the mobile terminal 130 may use the signalled values to derive its uplink transmission power.
• the power control parameters may be set according to the following method.
• the uplink output power PV for transmission in sub-frame "i" is derived by the mobile terminal 130 according to the following state of the art general expression:
• PT JL min ⁇ PTM ⁇ F(PL 1 , TPC 1 , Pl , p 2 ,-,P N ) ⁇ (1)
• PL path loss between the mobile terminal 130 and the radio network node 110, 120.
• TPC is the power control command received by the mobile terminal 130 from the radio network node 110 it may take one of the pre-defined values.
• P 1 N may be signalled to the mobile terminal 130 by the network.
• P ma ⁇ u E is the mobile terminal 130 maximum output power generally after applying maximum power reduction or after the so- called power back-off. It may be observed from (1) that the set of parameters (pi N ) if configured judiciously may be used to control the interference to the victim system. This is further elaborated below.
• PL is the path loss from the network node 110 to the mobile terminal 130.
• l J ma ⁇ may be the maximum acceptable interference to the victim system, "J”. Then the maximum allowed l J max may be achieved by limiting the power control parameters as follows:
• ⁇ J is the maximum value of the k m parameter (p ⁇ ⁇ ) in order to ensure the interference from mobile terminals 130 at the victim system "J" is below the maximum allowed level
• the set of maximum allowed power control parameter values (YI...N) may depend upon the victim system.
• This is the basic idea of the invention and is expressed by (2).
• One aspect is thus to find suitable values, which depend upon the victim system.
• Such a set of maximum values or a table may be pre-defined e.g. in a standard. Alternatively, according to some embodiments, it may be implemented as an algorithm at the radio network node 110,
• the radio network node 110, 120 may use the power control parameters under the constraints expressed by the pre-defined standardized table or the set.
• the set of "maximum allowed parameter values" to limit degradation in co-existence scenario may be standardized, according to some embodiments.
• the reason is that the interfering system and the victim system may belong to two different operators, as previously discussed.
• the standardized rules or set of parameter values may ensure that the performance of the victim system may not degrade below the limit, regardless of the coexistence scenarios e.g. E-UTRAN and UTRAN in adjacent carriers.
• each set which is applicable to a particular scenario comprising of an aggressor and a victim radio network, e.g. E-UTRAN and UTRAN FDD, is described in the following descriptive text.
• E-UTRAN uplink the setting of the terminal Transmit power P PUSCH for the physical uplink shared channel (PUSCH) transmission in subframe i is defined by:
• ⁇ PUSCH (0 min ⁇ MAX > 1 0 log] o (MPUS C H (0) + ⁇ O_PUSCH U) + cc ⁇ j) • PL + ⁇ TF (/) + /(/) ⁇ (3 )
• P ⁇ x is the maximum allowed power configured by higher layers.
• M PUSCH (z) is the bandwidth of the PUSCH resource assignment expressed in number of resource blocks valid for subframe /.
• ⁇ PREAMBLE _ hfsg i ma y be signalled from higher layers.
• a e ⁇ , 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, l ⁇ is a 3-bit cell specific parameter provided by higher layers.
• a(j) l.
• f(i) is a value resulting from the closed loop contribution of the power control.
• the admissible parameter region could depend on all of the parameters used in (3) except for the Path Loss (PL).
• the definition of the border of the region may be made as simple as possible. Therefore, according to some embodiments, the admissible region may only depend on the following two variables:
• N is the thermal noise power in one resource block.
• the admissible region for ⁇ and P 0 may be found e.g. by radio network simulations.
• the uplink power control on PUSCH channel is used as an example to determine the parameters, whose admissible values are to be determined and defined to limit the adjacent channel interference.
• Similar explanation may be applicable to other E-UTRA channels such as Physical Uplink Control CHannel (PUCCH), Sounding Reference Signal (SRS) and Physical Random Access CHannel (PRACH) etc.
• PUCCH Physical Uplink Control CHannel
• SRS Sounding Reference Signal
• PRACH Physical Random Access CHannel
• certain channels are more sensitive such as PUSCH since it may typically carry higher data rate.
• Table 1 illustrates some arbitrary and non-limiting examples of parameters concerning the possible admissible and/ or allowed values of the parameter ( ⁇ and P 0 ) in an urban environment, according to some embodiments.
• ISD inter site distance
• the region does not change with the inter-site distance (ISD) as long as the fraction of mobile terminals 130 experiencing a coupling loss to the serving base station 110, 120 that is equal to the minimum coupling loss does not change, or is sufficiently small.
• ISD inter-site distance
• Table 2 shows an illustrative example of some possible propagation parameters which may be defined for the rural environment, according to some embodiments. The corresponding results for the admissible region for ⁇ and P 0 , and the throughput for " ⁇ " are different.
• This region may comprise i.e. the urban propagation environment which may be more constraining than the rural one. This if the intention is to define only a single region that ensures the constraint on interference to UTRAN regardless of the propagation environment e.g. urban environment needs to be used.
• the present method concept may be that the maximum allowed interference at the victim system in a co-existence scenario, such as e.g. E- UTRA, UTRAN and GSM, could be achieved by limiting the values of one or more power control parameters at the interfering system.
• the restricted use of the power control parameter values may apply to the radio network node 110, 120 configuring or signalling the parameters to the mobile terminal 130 as may be the case in E-UTRAN.
• restriction or maximum allowed values may be taken into account by the mobile terminal 130 when deriving the parameters to be used for uplink power control.
• the constrained power control parameters' values may preferably pre-defined in the standard. Alternatively in the latter scenario they may be signalled to the mobile terminal 130.
• the present method is applicable in a system with good inter-user orthogonality within the same cell. This is due to the fact that in such system the mobile terminal transmission power, e.g. power distribution or average values may be higher and thus causing interference to the victim system.
• the present method may be particularly applicable to system based on OFDMA type technology e.g. OFDMA itself or SC-FDMA or the like.
• the power control admissible region in E-UTRAN may be enforced by two set of network signalled parameters: P 0 : Parameter constituting the target or expected receiver power at the radio network node 110, 120, where P 0 itself comprises of one or more network controlled parameters; and Cell specific parameter ( ⁇ ).
• the constraint on these power control parameters' values may be defined regardless of the propagation environment used.
• the constraint may be based on the most stringent environment e.g. comprising of highly dispersive radio channel. Another possibility may be to use the most typical or commonly used radio environment.
• constraint on the power control parameters' values may be defined to be specific to each radio environment or group of similar radio environments, such as e.g. group comprising of less dispersive and more dispersive channels and/ or lower terminal speed and higher terminal speed and/or higher or lower impact of the distance between the mobile terminal 130 and the network nodes 110, 120 on the path loss.
• the network Since the network is aware of the radio environment, it may use the most relevant set of constrained parameters in a given environment. These rules may be pre-defined in the standard i.e. maximum allowed parameters values for different radio environments. For instance multiple set of constrained parameters can be tied to the relevant radio environment and this relationship can be pre-defined. As an example set of parameters with low, i.e.
• maximum allowed values are most relaxed, medium and high level of constraint are specified to be followed in least dispersive, e.g. rural area, in somewhat dispersive e.g. sub-urban area and in most dispersive, e.g. typical urban or dense urban areas radio environments respectively.
• the constraint on the power control parameter values may be applied to all mobile terminals 130 regardless of whether they are using the Physical Resource Blocks (PRBs) at the edge of the channel bandwidth or not.
• PRBs Physical Resource Blocks
• the constraint may be applicable only for mobile terminals 130 using the physical resource blocks at the edge of the channel bandwidth.
• different set of constrained power control parameter values may be applied for mobile terminals 130 using physical resource blocks at the channel bandwidth edge and for mobile terminals 130 not using any physical resource blocks at the channel bandwidth edge.
• the constraint on the power control parameter values may be applied only to specific channel or specific set of channels e.g. PUSCH, PUCCH/PUSCH or SRS/PUSCH.
• the constraint may be applied regardless of the type of channel used for uplink transmission i.e. constrained power control parameter values are applicable for any type of transmission.
• channel specific constraint values such as i.e. different for different channels or group of channels, may be applied.
• the constraint on the power control parameters may be applied to mobile terminals 130 in the cell border region.
• the mobile terminal 130 in cell border region may be determined based on radio propagation conditions such as e.g. path loss, signal strength, signal quality etc. The reason is that such mobile terminals 130 may be expected to transmit at higher output power level.
• a threshold e.g. in terms of path loss, may be pre-defined in the standard and/ or implemented as an algorithm in the network. If terminal path loss is larger than the threshold, then the network may apply the constraint power control parameters.
• path loss or signal quality specific constrained values i.e. different set for mobile terminals 130 in cell border and those close to the radio network node 110, 120.
• the constrained on the power control parameters may be applied to the mobile terminal 130 which may transmit a data block larger than a certain threshold. This is because larger data block requires more transmission power contributing more interference at the adjacent channel.
• the constraint may be applicable regardless of the data block size used for uplink transmission.
• different set of constrained power control parameter values may be applied for different set of data block sizes e.g. values corresponding to small, medium and large block sizes.
• the constraint on the power control parameters may be applied depending upon the service in use.
• the mobile terminal 130 may typically operate at lower transmission power when using low bit rate service e.g. voice.
• large file upload may be characterized by large data block, which requires higher transmission power.
• the constrained on power control parameter values may be applied to service using large data block.
• service specific constrained values i.e. different sets for different type of services may be applied.
• the mobile terminal 130 may operate in Discontinuous Transmission Mode (DTX) and/or Discontinuous Reception Mode (DRX). This may be particularly more common for certain types of service e.g. Voice over IP (VoIP).
• VoIP Voice over IP
• the currently described embodiments may apply independent of the type of service.
• the constraint on the power control parameters' values may be applied depending upon the terminal transmission activity.
• a mobile terminal 130 with lower transmission activity may less severely interfere with the victim system in an adjacent channel.
• the constraint may be applied to the mobile terminal 130 whose data transmission activity is above a certain threshold value.
• different constrained power control parameters' values for different level of transmission activity may be levelled, applied e.g. different values for lower activity, medium activity and higher activity.
• the constrained power control parameters' values are to be applied by the first radio network node 110 only when any of the pre-defined co-existence scenarios, e.g. LTE, UTRAN and GSM, may be used.
• the constrained values are to be applied if there is UTRAN FDD operation in the operating band of the interfering system in a particular coverage area.
• there may be one set of constrained values regardless of the pre-defined co-existence scenario.
• the power control parameter values' may be specific for a co-existence scenario e.g. different for LTE-UTRAN, LTE-GSM etc.
• the constraint on the power control parameters' values may be applied by combining one or more of the previously described embodiments. For instance, different sets of constrained parameter values depending upon the type of service, activity, RB allocation such as e.g. whether at band edge or not, and so on.
• the combined scenario may be realized by specifying pre-defined rules in the standard e.g. lookup table containing various scenarios versus the corresponding set of power control parameter's values.
• the previous embodiments describe various constraints on the power control parameters' values used for uplink power control. However, these embodiments are also applicable for the downlink power control.
• the constraint on the parameter values will also be applicable to the radio network nodes 110, 120.
• the radio network nodes 110, 120 do not signal any parameter to the mobile terminal 130.
• the radio network node 110, 120 may itself transmit power in the downlink in accordance with the constrained set of downlink power control parameter values', which can be pre-defined in the standard according to one or more of the embodiments described previously or it can be an implementation algorithm in the radio network node 110, 120.
• power control parameter values may according to some different embodiments be determined according to different methods or alternative ways.
• the power control parameter determining unit has sufficient statistical knowledge of propagation environments in the interfering radio network and between the interfering radio network and the victim radio network. It also has the models of the interfering radio network power control algorithm.
• the determining unit can simulate the interference generated to the victim system.
• the power control parameter determining unit i.e. the simulator, may take as input the acceptable level of interference l J max to the victim system J.
• the unit adjusts power control parameter values in the simulation model such that the simulated interference is equal to the acceptable interference level.
• the unit varies the values of a subset of the parameter by specified amounts and then searches for values of the remaining subset of parameters such that the interference level is met again.
• the power control parameter values are selected and can be employed by the aggressor system for running the uplink power control.
• the power control parameter determining unit has measuring devices for measuring the interference from the interfering to the victim system. For a given set of power control parameter values the measuring device can measure the interference generated to the victim system. Like in alternative one, a subset of the power control parameters may be iteratively varied by specified amounts until the interference level at the victim system is reached within an acceptable range. The actual devices involved in tuning of power control parameters may be used e.g. during the periods of low traffic load in both interfering and victim radio network.
• the obtained power control parameter values for the target or acceptable interference such as i.e. l J max to the victim system "J" can be employed by the aggressor system for running the uplink power control.
• This relationship may be expressed in terms of a look up table or a mapping function or any suitable interpolation function, which is eventually used for setting the values of the power control parameters corresponding to the acceptable interference l J ma ⁇ at the victim system.
• Such a look up table or a mapping function based on the actual measured statistics may be regularly updated and may thereby optionally become more reliable over a period of time.
• the power control parameters may eventually be tuned and used at the aggressor system.
• both actual statistics of the measured interference at the victim system and the power control parameter values may be plugged in the simulator for fine tuning the eventual power control parameters to be used by the network.
• This means both actual measured statistics and the statistical models may be used to determine the actual power control parameters, which will ensure that the interference, i.e. l J max to the victim system "J" remain within the acceptable limit.
• this embodiment may be regarded as a combination of the preceding alternatives.
• the parameter set values found in this way may establish the vertices of a region of admissible parameter values.
• the border of the region may be found by connecting the vertices, e.g. such that the region is constrained by a set of linear inequalities in the parameter values.
• the region determining unit may determine the parameter value region just once before the interfering or victim system is brought into regular operation or periodically in order to track potential changes in the propagation environment or after network planning or whenever triggered by the operator.
• the object is achieved by a method in a first radio network node 110, adapted to operate on a first type of radio technology of controlling the uplink transmission power of one or more mobile terminals 130.
• the uplink power is at least partly controlled and configured by the signalling of one or more parameters to the mobile terminal 130.
• the method comprises the steps of:
• the first type of radio technology may according to some embodiments be any of E- UTRAN FDD or E-UTRAN TDD.
• the second type of radio technology may according to some embodiments be any of UTRAN FDD, UTRAN TDD or GSM. Also, the object may be achieved by a method according to any of the embodiments above, wherein the constrained power control parameters comprise one or more cell specific parameters and parameters related to the target received power or interference level at the first radio network node 110 of interfering technology.
• the object may be achieved by a method according to any of the embodiments above wherein the constrained power control parameters' values are applied or specific to one or more of the following scenario: the mobile terminal 130 using resource blocks at the edge of transmission bandwidth, type of service, the mobile terminal 130 transmission and/ or reception activity levels, data block size, the mobile terminal 130 position or path loss between the mobile terminal 130 and serving radio network node 110, co-existence scenario or any combination thereof.
• Figure 2 is a flow chart illustrating a method in a first radio network node 110, according to some embodiments.
• the method aims at supporting transmission power adjustment of a mobile terminal 130 in order to reduce interference caused by the mobile terminal 130 on a second radio network node 120.
• the second radio network node 120 is situated at the same geographical location 100 as the first radio network node 110.
• the first radio network node 110 and the mobile terminal 130 are configured for operation on a first radio access technology while the second radio network node 120 is configured for operation on a second radio access technology.
• the first type of radio access technology may according to some embodiments be any of E-UTRAN FDD or E-UTRAN TDD.
• the second type of radio access technology may according to some embodiments be any of UTRAN FDD, UTRAN TDD or GSM.
• the first radio network node 110 and the second radio network node 120 may operate in adjacent carrier frequencies or adjacent radio frequency channels, according to some embodiments.
• the method in the first radio network node 110 may comprise a number of steps 201-203. It is however to be noted that some of the described method steps are optional and only comprised within some embodiments. Further, it is to be noted that the method steps 201- 203 may be performed in any arbitrary chronological order and that some of them, e.g. step 201 and step 202, or even all steps may be performed simultaneously or in an altered, arbitrarily rearranged, decomposed or even completely reversed chronological order. The method may comprise the following steps:
• An indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130 is obtained.
• This step may optionally be based on an estimation, concerning the radio traffic situation within the geographical location 100.
• this step may optionally comprise determining the category of environment, such as e.g. rural area, urban area, wherein the geographical location 100 is situated. Further, the radio traffic load at the geographical location 100 may be estimated, e.g. determined to be "low", “medium” or "high".
• this step may comprise measurements, such that the indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130 may be based on a measurement which may be performed e.g. by the first radio network node 110 and/or the second radio network node 120 and signalled to the first radio network node 110.
• Step 202 Values of power control parameters for adjusting the transmission power of the mobile terminal 130 are obtained.
• such values of power control parameters may be based on previously assembled statistical data concerning different radio propagation conditions at the geographical location 100 such as e.g. rural area or urban area assumptions.
• the values of power control parameters may be obtained from a look up table, where appropriate values of power control parameters previously have been assembled.
• the step of obtaining values of power control parameters may be based on measurements, which may be performed e.g. by the first radio network node 110 and/or the second radio network node 120 and signalled to the first radio network node 110.
• the values of power control parameters may depend upon the size of the data block transmitted in the uplink.
• the values of power control parameters may depend upon the characteristics and/or activity level of the service used in the uplink.
• the obtained power control parameter values are transmitted to the mobile terminal 130, in order to enable the adjustment of the transmission power of the mobile terminal 130.
• the transmission power of the first radio network node 110 may be adjusted in order to avoid or at least reduce interference with the second radio network node 120.
• Figure 3 is a block diagram illustrating embodiments of an arrangement 300 situated in a first radio network node 110.
• the first radio network node 110 is adapted to operate on a first radio access technology.
• the arrangement 300 is configured to perform the method steps 201-203 for supporting transmission power adjustment of a mobile terminal 130 in order to reduce interference caused by the mobile terminal 130 on a second radio network node 120.
• the second radio network node 120 is adapted to operate on a second radio access technology.
• the arrangement 300 comprises a first obtaining unit 310.
• the first obtaining unit 310 is adapted to obtain an indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130.
• the arrangement 300 comprises a second obtaining unit 320.
• the second obtaining unit 320 is adapted to obtain values of power control parameters for adjusting the transmission power of the mobile terminal 130.
• the arrangement 300 comprises a transmitter 330.
• the transmitter 330 is adapted to transmit the obtained power control parameter values to the mobile terminal 130, in order to enable the adjustment of the transmission power of the mobile terminal 130.
• the arrangement 300 may according to some embodiments comprise a processing unit 350.
• the processing unit 350 may be represented by e.g. a Central Processing Unit (CPU), a processor, a microprocessor, or other processing logic that may interpret and execute instructions.
• the processing unit 350 may perform all data processing functions for inputting, outputting, and processing of data including data buffering and device control functions, such as call processing control, user interface control, or the like.
• the arrangement 300 optionally may comprise a receiver 340, adapted to receive radio signal.
• the described units 310-350 comprised within the arrangement 300 may be regarded as separate logical entities, but not with necessity as separate physical entities. Any, some or all of the units 310-350 may be comprised or co-arranged within the same physical unit. However, in order to facilitate the understanding of the functionality of the arrangement 300, the comprised units 310-350 are illustrated as separate physical units in Figure 3.
• the transmitter 330 and e.g. the receiver 340 may, according to some embodiments, be comprised within one physical unit, a transceiver, which may comprise a transmitter circuit and a receiver circuit, which respectively transmits outgoing radio frequency signals to the mobile terminals 130 and receives incoming radio frequency signals from the mobile terminals 130 via an optional antenna.
• the antenna may be an embedded antenna, a retractable antenna or any other arbitrary antenna without departing from the scope of the present arrangements.
• the method steps 201-203 in the first radio network node 110 may be implemented through one or more processing units 350 in the first radio network node 110, together with computer program code for performing the functions of the present method steps 201-203.
• a computer program product comprising instructions for performing the method steps 201-203 in the first radio network node 110 may perform the described method for supporting transmission power adjustment of a mobile terminal 130, when being loaded into the processing unit 350 in the first radio network node 110.
• the computer program product mentioned above may be provided for instance in the form of a data carrier carrying computer program code for performing the method steps 201-
• the data carrier may be e.g. a hard disk, a CD ROM disc, a memory stick, an optical storage device, a magnetic storage device or any other appropriate medium such as a disk or tape that can hold machine readable data.
• the computer program product may furthermore be provided as computer program code on a server and downloaded to the first radio network node 110 remotely.
• the computer program product comprises instructions for obtaining an indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130. Also, the computer program product comprises instructions for obtaining values of power control parameters for adjusting the transmission power of the mobile terminal 130. In addition, the computer program product comprises instructions for transmitting the obtained power control parameter values to the mobile terminal 130, in order to enable the adjustment of the transmission power of the mobile terminal 130, when the computer program product is run on a processing unit 350 comprised within the first radio network node 110, when being loaded into the processing unit 350 in the first radio network node 110.
• Figure 4 is a flow chart illustrating a method in a second radio network node 120, according to some embodiments. The method aims at assisting a first radio network node
• the first radio network node 110 in supporting transmission power adjustment of a mobile terminal 130 in order to reduce interference, caused by the mobile terminal 130.
• the first radio network node 110 and the second radio network node 120 are situated at the same geographical location
• the first radio network node 110 and the mobile terminal 130 are configured for operation on a first radio access technology while the second radio network node 120 is configured for operation on a second radio access technology.
• the first type of radio access technology may according to some embodiments be any of E-UTRAN FDD or E-UTRAN TDD.
• the second type of radio access technology may according to some embodiments be any of UTRAN FDD, UTRAN TDD or GSM.
• the method in the second radio network node 120 may comprise a number of steps 401-404. It is however to be noted that some of the described method steps 401-404 are optional and only comprised within some embodiments. Further, it is to be noted that the method steps 401-404 may be performed in any arbitrary chronological order and that some of them, e.g. step 401 and step 402, or even all steps may be performed simultaneously or in an altered, arbitrarily rearranged, decomposed or even completely reversed chronological order.
• the method may comprise the following steps:
• the signal interference, induced by the mobile terminal 130, is measured.
• An indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130 is sent to the first radio network node 110, if the measured signal interference from the mobile terminal 130 exceeds a certain predetermined threshold limit value.
• the values of the power control parameters of the mobile terminal 130 may optionally be estimated in order to avoid or at least reduce interference.
• the estimated power control parameters of the mobile terminal 130 may according to some embodiments be transmitted to the first radio network node 110.
• Figure 5 is a block diagram illustrating embodiments of an arrangement 500 situated in a second radio network node 120.
• the arrangement 500 is configured to perform the method steps 401-404 for assisting a first radio network node 110 in supporting transmission power adjustment of a mobile terminal 130.
• the first radio network node 110 and the mobile terminal 130 are adapted to operate on the first radio access technology.
• the second radio network node 120 is adapted to operate on a second radio access technology.
• any internal electronics of the arrangement 500, not completely necessary for understanding the present solution has been omitted from Figure 5.
• the arrangement 500 comprises a measuring unit 510.
• the measuring unit 510 is adapted to measure the signal interference induced by the mobile terminal 130 on the second radio network node 120.
• the arrangement 300 comprises a transmitter 520.
• the transmitter 520 is adapted to transmit an indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130, if the measured signal interference from the mobile terminal 130 exceeds a certain predetermined threshold limit value.
• the arrangement 500 may comprise an estimating unit 530.
• the optional estimating unit 530 may be adapted to estimate the appropriate values of the power control parameters of the mobile terminal 130, in order to avoid or at least reduce interference with the second radio network node 120.
• the arrangement 500 optionally may comprise a receiver 540, adapted to receive radio signals.
• the arrangement 500 may according to some embodiments comprise a processing unit 550.
• the processing unit 550 may be represented by e.g. a Central Processing Unit (CPU), a processor, a microprocessor, or other processing logic that may interpret and execute instructions.
• the processing unit 550 may perform all data processing functions for inputting, outputting, and processing of data including data buffering and device control functions, such as call processing control, user interface control, or the like.
• the described units 510-550 comprised within the arrangement 500 may be regarded as separate logical entities, but not with necessity as separate physical entities. Any, some or all of the units 510-550 may be comprised or co-arranged within the same physical unit. However, in order to facilitate the understanding of the functionality of the arrangement 500, the comprised units 510-550 are illustrated as separate physical units in Figure 5.
• the transmitter 520 and e.g. the receiver 540 may, according to some embodiments, be comprised within one physical unit, a transceiver, which may comprise a transmitter circuit and a receiver circuit, which respectively transmits outgoing radio frequency signals to e.g. the mobile terminal 130 and receives incoming radio frequency signals from e.g. the mobile terminal 130 via an optional antenna.
• the method steps 401-404 in the second radio network node 120 may be implemented through one or more processing units 550 in the second radio network node 120, together with computer program code for performing the functions of the present steps 401-404.
• a computer program product comprising instructions for performing the method steps 401-404 in the second radio network node 120 may perform a method for assisting a first radio network node 110 in supporting transmission power adjustment of a mobile terminal 130, when the computer program product is run on a processing unit 550 comprised within the second radio network node 120.
• the computer program product mentioned above may be provided for instance in the form of a data carrier carrying computer program code for performing the method steps 401- 404 according to the present solution when being loaded into the processing unit 550.
• the data carrier may be e.g. a hard disk, a CD ROM disc, a memory stick, an optical storage device, a magnetic storage device or any other appropriate medium such as a disk or tape that can hold machine readable data.
• the computer program product may furthermore be provided as computer program code on a server and downloaded to the second radio network node 120 remotely, e.g. over an Internet or an intranet connection.
• the computer program product comprises instructions for performing measurement of the signal interference induced by the mobile terminal 130 on the second radio network node 120. Also, the computer program product comprises instructions for sending an indication that the second radio network node 120 is interfered by transmissions from the mobile terminal 130 to the first radio network node 110, if the measured signal interference from the mobile terminal 130 exceeds a certain predetermined threshold limit value, when the computer program product is run on a processing unit 550 comprised within the second radio network node 120.

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• 2009
  • 2009-06-23 CN CN200980156771.7A patent/CN102308610B/zh not_active Expired - Fee Related
  • 2009-06-23 JP JP2011549115A patent/JP5747285B2/ja not_active Expired - Fee Related
  • 2009-06-23 EP EP09839777.1A patent/EP2394455A4/de not_active Withdrawn
  • 2009-06-23 US US13/148,433 patent/US8880112B2/en not_active Expired - Fee Related
  • 2009-06-23 WO PCT/SE2009/050790 patent/WO2010090567A1/en active Application Filing

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